processes plugin: Fixed handling of ProcessMatch regexes containing spaces.

processes plugin: Fixed handling of ProcessMatch regexes containing spaces.

Previously, something like 'ProcessMatch name "My Regex"' would have been
interpreted as three values. This was caused by using the old, non-complex
config interface which joins all config values using a space and passing the
resulting string to the plugin. The processes plugin used to use strsplit() to
re-gain a list of all values, obviously ignoring any quoting that might exist.

This has been fixed by using the complex config interface, which passes all
values as an array of strings and thus honoring the quoting handled by
liboconfig.